The present invention generally relates to rotor assemblies for rotary fluid devices such as pumps, flowmeters, turbines, and mixers for use in hygienic and sanitary applications, and more particularly to rotor assemblies having two or more parts that are connected in a sealed configuration.
It is known to one skilled in the prior art that a rotor assembly may include two or more parts in order to reduce production and maintenance costs, enable the utilization of materials with optimal physical properties, and improve interchangeability. Such arrangements often are located within a region of the rotary device that places the rotor assembly in contact with a process fluid. This is disadvantageous if the rotary fluid device is intended for use in hygienic and sanitary applications, because such a rotor assembly should be free from pockets, gaps, and crevices that are in contact with process fluid, which may promote microbial growth or collection of soil, leading to contamination of the fluid.
Multiple-part rotor assemblies for rotary fluid devices in the prior art generally include a number of elements which can prevent usage in sanitary and hygienic applications, such as, traditional fasteners, for instance socket head screws, exposed threads, interference fits used to assemble parts with non-circular cross sections, shoulders, or relieved areas, and unsealed adjacent surfaces through which process fluid does not normally flow.
As such, prior art rotary fluid devices that are designed for use in hygienic and sanitary applications typically have been designed without multiple-part rotor assemblies or with multiple-part rotor assemblies joined by polished welds, so as to comply with industry regulations regarding cleanliness, thus sacrificing the potential benefits that otherwise may be available in multiple-part rotor assemblies.
The present disclosure seeks to overcome the shortcomings of the prior art to realize a rotor assembly that is useful and suitable for hygienic and sanitary applications.